| /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ |
| /* |
| * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved. |
| * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved. |
| */ |
| |
| #ifndef RXE_QUEUE_H |
| #define RXE_QUEUE_H |
| |
| /* implements a simple circular buffer that can optionally be |
| * shared between user space and the kernel and can be resized |
| |
| * the requested element size is rounded up to a power of 2 |
| * and the number of elements in the buffer is also rounded |
| * up to a power of 2. Since the queue is empty when the |
| * producer and consumer indices match the maximum capacity |
| * of the queue is one less than the number of element slots |
| */ |
| |
| /* this data structure is shared between user space and kernel |
| * space for those cases where the queue is shared. It contains |
| * the producer and consumer indices. Is also contains a copy |
| * of the queue size parameters for user space to use but the |
| * kernel must use the parameters in the rxe_queue struct |
| * this MUST MATCH the corresponding librxe struct |
| * for performance reasons arrange to have producer and consumer |
| * pointers in separate cache lines |
| * the kernel should always mask the indices to avoid accessing |
| * memory outside of the data area |
| */ |
| struct rxe_queue_buf { |
| __u32 log2_elem_size; |
| __u32 index_mask; |
| __u32 pad_1[30]; |
| __u32 producer_index; |
| __u32 pad_2[31]; |
| __u32 consumer_index; |
| __u32 pad_3[31]; |
| __u8 data[]; |
| }; |
| |
| struct rxe_queue { |
| struct rxe_dev *rxe; |
| struct rxe_queue_buf *buf; |
| struct rxe_mmap_info *ip; |
| size_t buf_size; |
| size_t elem_size; |
| unsigned int log2_elem_size; |
| unsigned int index_mask; |
| }; |
| |
| int do_mmap_info(struct rxe_dev *rxe, struct mminfo __user *outbuf, |
| struct ib_udata *udata, struct rxe_queue_buf *buf, |
| size_t buf_size, struct rxe_mmap_info **ip_p); |
| |
| void rxe_queue_reset(struct rxe_queue *q); |
| |
| struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, |
| int *num_elem, |
| unsigned int elem_size); |
| |
| int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p, |
| unsigned int elem_size, struct ib_udata *udata, |
| struct mminfo __user *outbuf, |
| /* Protect producers while resizing queue */ |
| spinlock_t *producer_lock, |
| /* Protect consumers while resizing queue */ |
| spinlock_t *consumer_lock); |
| |
| void rxe_queue_cleanup(struct rxe_queue *queue); |
| |
| static inline int next_index(struct rxe_queue *q, int index) |
| { |
| return (index + 1) & q->buf->index_mask; |
| } |
| |
| static inline int queue_empty(struct rxe_queue *q) |
| { |
| return ((q->buf->producer_index - q->buf->consumer_index) |
| & q->index_mask) == 0; |
| } |
| |
| static inline int queue_full(struct rxe_queue *q) |
| { |
| return ((q->buf->producer_index + 1 - q->buf->consumer_index) |
| & q->index_mask) == 0; |
| } |
| |
| static inline void advance_producer(struct rxe_queue *q) |
| { |
| q->buf->producer_index = (q->buf->producer_index + 1) |
| & q->index_mask; |
| } |
| |
| static inline void advance_consumer(struct rxe_queue *q) |
| { |
| q->buf->consumer_index = (q->buf->consumer_index + 1) |
| & q->index_mask; |
| } |
| |
| static inline void *producer_addr(struct rxe_queue *q) |
| { |
| return q->buf->data + ((q->buf->producer_index & q->index_mask) |
| << q->log2_elem_size); |
| } |
| |
| static inline void *consumer_addr(struct rxe_queue *q) |
| { |
| return q->buf->data + ((q->buf->consumer_index & q->index_mask) |
| << q->log2_elem_size); |
| } |
| |
| static inline unsigned int producer_index(struct rxe_queue *q) |
| { |
| return q->buf->producer_index; |
| } |
| |
| static inline unsigned int consumer_index(struct rxe_queue *q) |
| { |
| return q->buf->consumer_index; |
| } |
| |
| static inline void *addr_from_index(struct rxe_queue *q, unsigned int index) |
| { |
| return q->buf->data + ((index & q->index_mask) |
| << q->buf->log2_elem_size); |
| } |
| |
| static inline unsigned int index_from_addr(const struct rxe_queue *q, |
| const void *addr) |
| { |
| return (((u8 *)addr - q->buf->data) >> q->log2_elem_size) |
| & q->index_mask; |
| } |
| |
| static inline unsigned int queue_count(const struct rxe_queue *q) |
| { |
| return (q->buf->producer_index - q->buf->consumer_index) |
| & q->index_mask; |
| } |
| |
| static inline void *queue_head(struct rxe_queue *q) |
| { |
| return queue_empty(q) ? NULL : consumer_addr(q); |
| } |
| |
| #endif /* RXE_QUEUE_H */ |